HBV all true, except:
**Core Concept**
HBV (Hepatitis B Virus) is a major public health concern worldwide, causing both acute and chronic liver disease. It is a DNA virus that replicates in the liver cells, leading to inflammation and potential liver cirrhosis or hepatocellular carcinoma.
**Why the Correct Answer is Right**
HBV infection is primarily spread through bodily fluids, such as blood and semen, during unprotected sex, needle sharing, or vertical transmission from mother to child during childbirth. The virus enters the liver cells through the CD4 receptor, where it hijacks the host cell machinery to replicate. The HBV genome encodes for several proteins, including the surface antigen (HBsAg), e antigen (HBeAg), and core antigen (HBcAg), which are used as markers for diagnosis and monitoring.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because HBV is not primarily spread through fecal-oral transmission like hepatitis A virus (HAV).
**Option B:** This option is incorrect because HBV infection is not primarily asymptomatic in adults, although it can be in newborns.
**Option C:** This option is incorrect because HBV is not a RNA virus; it is a DNA virus.
**Clinical Pearl / High-Yield Fact**
The HBV vaccine is a highly effective measure to prevent HBV infection, and it is recommended for all healthcare workers, individuals with multiple sex partners, and those who inject illicit drugs.
**Correct Answer: A. HBV is primarily spread through fecal-oral transmission like hepatitis A virus (HAV).